The present invention relates to devices for dispensing, delivering, injecting, infusing or administering substances, and to methods of making and using such devices. More particularly, it relates to a device for administering a fluid product in doses, comprising a torsion spring drive. In some embodiments, the device or apparatus of the present invention may be an injection apparatus, e.g., an injection pen.
Injection apparatus or devices are known from diabetes therapy, administering growth hormones or osteoporosis preparations. Such apparatus should guarantee that the correct dosage is administered, yet be simple and convenient to operate. These requirements are particularly important when a user administers the relevant product him/herself.
Injection apparatus, such as one known for from WO 01/10484, comprise a conveying means, a dosing means and a drive means. The user applies the drive force required for administering the product him/herself, by charging the drive means with the drive force. The drive means is coupled to the conveying means such that the drive force introduced is converted into a conveying action of the conveying means.
An injection apparatus follows from WO 02/053214 A1 which uses a drive spring to generate the drive force, wherein said drive spring is tensed for setting the dosage and releases the stored energy during delivery. A spring which is wound around an axis in a spiral serves as the drive spring, the windings of which lie adjacently along the axis. Due to the drive spring, the user no longer has to apply the drive force and can thus better concentrate on the other manual operations required for administering. On the other hand, the injection apparatus can only administer a fixedly predetermined dosage.